This invention is a medical device, specifically used in surgery. It is a wire having distal radio-opaque markers and may be used, for instance, in endovascular procedures as a marker wire for estimating or referencing the structural attributes of internal physical features. In addition, the inventive marker wire may be used as a guide wire for a catheter used in endovascular procedures.
This invention is a wire having many of the aspects of a guidewire as suitably used with a catheter in accessing remote regions of the human vasculature. More importantly, the inventive wire includes a number of markers situated near the distal tip of the wire that are visible using a fluoroscope or other x-ray apparatus. The markers are spaced in such a way as to allow comparison with some internal physical attribute or feature in the human body.
Placement of radio-opaque markings on surgical guidewires or needles is shown, for instance, in U.S. Pat. No. 5,409,004, to Sloan. Sloan shows the use of a needle useful as a localization device designed to depict the location and depth of lesions found during a mammogram. The markers may be coated onto the needle in such a way that the lesion""s specific depth may be reviewed in a fluoroscope or the needle may have specifically formed grooves allowing one to observe that a location is, e.g., 3 cm. from the surface by noting that the needle markers have a set of three rings near the surface of the body.
A catheter having radio-opaque markers for xe2x80x9cmeasurements of the distance between a first target location and a second target locationxe2x80x9d is shown in U.S. Pat. No. 5,860,923, to Linker et al.
Various guidewires or other medical wires including fluoroscopically viewable sectors are also known.
U.S. Pat. No. 5,253,653, to Daigle et al, shows a guidewire having a series of markers placed near the distal tip of the device typically within the interior of a coil. The markers are mounted on the wire itself by welding, soldering, or brazing.
Similarly, U.S. Pat. No. 5,606,981, to Tartacower et al, describes a device in which the markers variously are placed beneath a polymer sleeve but directly upon the wire core. Alternatively, a radio-opaque coil having a varying pitch along its length. The more tightly wound sections are more visible in the fluoroscope. A polymeric sleeve covers the coil.
U.S. Pat. No. 5,836,892 to Lorenzo, shows a guidewire having two or more radio-opaque marker bands placed directly onto the core wire and separated by plastic tubing segments. The marker bands are also covered by a polymeric sleeving.
Finally, U.S. Pat. No. 6,068,623, to Zadno-Azizi et al, suggests placement of xe2x80x9ca series of radio-opaque markers . . . on the body of guidewire (12) as indicated in FIG. 3.xe2x80x9d It is further suggested that the markers (22) xe2x80x9c. . . can be embodied in the wall of catheter (12) or applied as plating to a reduced diameter portion thereof in order to maintain its smooth outer profile.xe2x80x9d
None of the cited references suggest the marker wire structure as described herein.
This invention is a marker wire for radiological use. It may be used, for instance, as a reference tool in identifying or estimating structural features in the human body. It is made up of a flexible, elongate core wire having a distal end, a proximal end, an outer surface, and a length extending between the distal end and the proximal end. The core wire has at least one polymeric covering extending proximally from the distal end that is in contact with that outer surface for at least a portion of the core wire length. Desirably, the inventive marker wire has a substantially constant diameter along most of its length.
In particular, the marker wire includes a plurality of radio-opaque markers desirably placed exterior to at least one of the polymeric coverings near the distal end of the core wire. The radio-opaque markers are of a size, shape, and placement suitable for allowing estimation of a distance near or in the body lumen along the marker wire. Estimation of a marker wire distance may be instructive, for instance, in judging or estimating an aneurysm neck size or diameter.
The core wire, preferably stainless steel, may include a metallic ribbon extending distally from the core wire distal end and preferably includes at least one tapered section.
The radio-opaque markers may be helical coils of radio-opaque wire or ribbon or bands of radio-opaque metal, alloy, or polymer containing a radio-opacifier.
The radio-opaque markers may be separated from each other by comparatively radio-lucent spacers such as coils or bands of stainless steel or polymer.